Once you start doing focus stacking, especially if you increase in magnification, you will likely soon tire of the manual adjustments and will be looking for an automated solution. With respect to your statements about not wanting to go automated right away, I can only suggest to minimize your expenditures for the manual focus rail by buying an inexpensive one that will adequately do your initial work at 1:1 but doesn't offer the precision required for higher magnifications. I would still concentrate on getting a worm gear driven rail, rather than a rack and pinion type, since they are more precise, especially if they have a large-ish knob.

The above is excellent advice. I know from experience.

I wouldn't spend a lot of money on a manual rail, as one that's really precise and repeatable is going to approach or exceed the cost of something like a Wemacro.

At high magnifications, stacking with a manual rail is going to get VERY tedious. With a manual rail cheaper than a Wemacro, it's going to become maddening.

I used a cheap Chinese rail from eBay for a few years, mostly for single images. It was great for fine focusing for single shots. On those few occasions when I tried to do stacking with it, it was an exercise in frustration.

An alternative to (and an intermediate step towards) an automated rail is automated tethering software like DSLR Controller (for Canon and Android). The software is usually very reasonably priced, and allows you (with the appropriate autofocus lens) to do focus stacking with an inexpensive rail or no rail at all. There are a number of such apps, for PCs (Windows, Linux, and Apple), and for phones and tablets (Android and iPhone).

If it were me, I wouldn't spend more than about $50usd on a manual rail. I'd buy tethering software and save my money for a Wemacro or Stackshot.

I got this via aliexpress and it is much worse than the Ishoot. The rail wobbles and can not be tightened. It also has no quick release on the worm gear so you have to screw it all the way up and down.

I got this via aliexpress and it is much worse than the Ishoot. The rail wobbles and can not be tightened. It also has no quick release on the worm gear so you have to screw it all the way up and down.

Would have been nice to know ahead of my order, but I'll give it a go nevertheless.

No worries, though it does create a new project for me. I plan to modify the Mengs to see if I can make a decent vertical rail out of it. All my systems are vertical, since it's convenient/desirable to place a coin flat on the imaging stage. The weight of the camera (if camera is moved) or stage (if camera is held fixed) holds the screw tight against the upward force of the screw, so this essentially eliminates screw backlash. Wobble remains the biggest issue for vertical setups, so I'm looking to fix that on the Mengs rail. Turns out the rail has a nice arrangement of precision 4mm optical rods, one on each side of the screw. I think that linear bearings can be added to make the stage stable.

So bottom line the Mengs project is to add linear bearings. If the stability is good then add a stepper on one end, leaving the other end with larger screw knob.

No worries, though it does create a new project for me. I plan to modify the Mengs to see if I can make a decent vertical rail out of it. All my systems are vertical, since it's convenient/desirable to place a coin flat on the imaging stage. The weight of the camera (if camera is moved) or stage (if camera is held fixed) holds the screw tight against the upward force of the screw, so this essentially eliminates screw backlash. Wobble remains the biggest issue for vertical setups, so I'm looking to fix that on the Mengs rail. Turns out the rail has a nice arrangement of precision 4mm optical rods, one on each side of the screw. I think that linear bearings can be added to make the stage stable.

So bottom line the Mengs project is to add linear bearings. If the stability is good then add a stepper on one end, leaving the other end with larger screw knob.